Keystone Tablet Punch can be purchased at Claims to be:

  • Composed entirely of 304-grade stainless steel
  • Fireproof threshold of 1399 to 1455°C / 2550 to 2651°F
  • Corrosion Resistant
  • Waterproof


Setup was quite easy and only took a few minutes.

Heat Stress Test

The divots are still legible, though there’s a concerning amount of “noise” appearing on the plates.

Corrosion Stress Test

This test was rough on the Keystone Tablet Punch. Most of the lines, letters, and numbers disappeared. Even worse, there is so much noise now that it is very difficult to tell which spots on the plate are the real ones for the seed data. It would be extremely challenging to recover this data.

Crush Stress Test

The crushing itself caused no data loss, though you can see that after leaving the plates outside for a few weeks, the corrosion worsened significantly.